java 实现读取clob

 import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.sql.Clob;

 public List> queryForList() { List> rowList = new ArrayList>(); String driver = ""; String url = ""; String username = ""; String password = ""; String sql = ""; log.info("查询sql条件：" + sql); try { // 加载驱动程序，此处运用隐式注册驱动程序的方法 Class.forName(driver); log.info("加载驱动成功！"); } catch (ClassNotFoundException e) { log.error("加载驱动程序，此处运用隐式注册驱动程序的方法出错：" + e.getMessage()); e.printStackTrace(); } try { // 创建连接对象 Connection con = DriverManager.getConnection(url, username, password); // 创建sql执行对象 Statement st = con.createStatement(); // 执行sql语句并返回结果集 ResultSet rs = st.executeQuery(sql); // 获得结果集结构信息,元数据 ResultSetMetaData rsmd = rs.getMetaData(); // 获得列数 int columnCount = rsmd.getColumnCount(); // 用于接收每行数据 Map rowData = null; // clob类型 Clob clob = null; // clob转成String String clobString = ""; while (rs.next()) { rowData = new HashMap(); for (int i = 1; i <= columnCount; i++) { // 判断数据类型是否为Clob if (rs.getObject(i) instanceof Clob) {// Clob转String clob = (Clob) rs.getObject(i); clobString = clob.getSubString((long) 1, (int) clob.length()); rowData.put(rsmd.getColumnName(i), clobString); } else { rowData.put(rsmd.getColumnName(i), rs.getObject(i)); } } rowList.add(rowData); } // 关闭相关的对象 if (rs != null) { rs.close(); } if (st != null) { st.close(); } if (con != null) { con.close(); } } catch (SQLException e) { e.printStackTrace(); } return rowList; }